Hi, HIO Welcome to the conversation. That's a good question and...

Hi, HIO
Welcome to the conversation.
That's a good question and one that the company has given a couple of mentions to, though without a clear answer (imo ).
They have at different times stated that mining could continue concurrently with the PHES project . They have also stated that it would mean a discount to production.
The bottom reservoir only requires a relatively small volume of the pit and access to any? (Or some) of the underground targets would be above that water level - so no real problem there.
As an incoming operator of the PHES I am sure it would not be seen as quite that simple (and vice/versa from a continued mining scenario) with assurances of one not adversely impacting the other being required. It may well be that the hope is for the regional prospects to negate the need to pursue the under pit targets depending, of course, on the merits and results of each (in respect of proved up grades and resrerves). My best guess is that, in the event of a serious expression of interest ( read - offer) from an outside party on the PHES , there will be some very interesting and complicated discussion on the pros and cons of the various options.
In other words, I have no idea what the outcome will be!
Cheers, Foyt